The present invention relates in general to pumping devices for pumping liquid or gaseous or plastic fluids or mixtures of solids and gaseous or liquid fluids, and more particularly to wave pump assemblies having a rotor member in the form of a helix with smooth, rounded threads and means activated by the helix to generate a continuous wave motion providing longitudinally moving pockets for moving the medium to be pumped.
Heretofore, various pumping devices have been proposed to effect pumping of a medium, such as liquid or gaseous fluids of various types, by a pump structure involving a helical rotor, usually having rounded helical threads, and a stator also providing a bore which is of rounded helical configuration having a different pitch from the helical rotor, providing pumping pockets which progress longitudinally from the input end to the output end of the pump. A number of such pump devices have been developed and marketed by Robins & Myers Inc. of Springfield, Ohio, under the name Moyno gear pumps, involving principles of pump structure disclosed in various U.S. patents to R. J. L. Moineau. Examples of these patents are U.S. Pat. Nos. 1,892,217 and 2,028,407.
However, certain disadvantages have been identified as in an inherent property of that type of construction. With the Moineau type pump, either the rotor or the stator must be free to orbit around the center of rotation of the input drive shaft or other driving mechanism. This is because of the nature of the Moineau type pump wherein the confronting surfaces of the rotor and stator are rounded helical thread configurations of different pitch providing pumping pockets which progress longitudinally from the input to the output end of the positive displacement pump mechanism. Because of the necessity of enabling either the rotor or the stator, usually the rotor, to orbit around the center of rotation of the input shaft, a rather complex coupling must be provided between the drive shaft and the input end of the rotor of the pump mechanism to allow this relative movement of the center of rotation of the pump rotor relative to the center of rotation of the drive shaft.
An object of the present invention is the provision of a novel positive displacement pump assembly employing a helical rotor with smooth rounded helical threads, which eliminates the need for a coupling to accommodate orbiting of the pump rotor, and provides for greater capacity for a given rotor length and thread pitch than Moineau type pumps, and provides continuous and positive displacement pumping of the fluid or other flow medium by generating a continuous wave motion providing volume displacement which is utilized more efficiently to pump the medium.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.